Cut-to-length apparatus for bias-cut tire belt ply material

ABSTRACT

An apparatus for the contemporaneous bias-cutting of two elongated strips of rubberized tire belt or breaker ply material with reinforcing elements of opposed bias angles into relatively shorter belt ply-forming strips of predetermined lengths, each starting strip being cut from its middle toward its opposite edges. The apparatus includes two coaxial, rotatable, cylindrical drum-like anvils for the starting strips, and two pairs of normally retracted, non-rotary, heated cutting blades, the two blades of each pair being mounted for joint reciprocal opposed movements along a respective curved path the obliquity of the plane of which relative to the mid-circumferential plane of the associated drum can be adjusted, preferably about an axis located in the mid-circumferential plane of the associated drum and perpendicular to the drum axis, so as to correspond to any desired one of a range of such bias angles. The curvature of each path is such that in the mean adjusted position thereof it is disposed at a substantially constant spacing from the associated drum surface. The cutting blades of each pair are arranged to abut against each other at the mid-point of their respective path of movement, with the parting line of their cutting edge tip region in line with the associated pivot axis, so that any underlying strip is penetrated in the middle thereof when the blades are protracted against the associated drum surface. Suitable means are also provided for yieldingly urging the blades continuously into contact with the associated drum surfaces during the separating movements of the blades while performing the cutting operation so as to compensate for variations in the spacing between their paths of movement and the drum surfaces engendered by angular adjustments of the paths to other than the mean adjusted positions thereof.

States Patent 1 Habert 51 May 15, 1973 CUT-TO-LENGTH APPARATUS FORBlAS-CUT TIRE BELT PLY MATERIAL [75] Inventor: William C. l-labert,Fraser, Mich.

[73] Assignee: Uniroyal, Inc., New York, NY.

[22] Filed: Nov. 26, 1971 [21] Appl. No.: 202,163

Primary Examiner Frank T. Yost A ttoihyg NorbertP. Holler [57] ABSTRACTAn apparatus for the contemporaneous bias-cutting of two elongatedstrips of rubberized tire belt or breaker ply material with reinforcingelements of opposed bias angles into relatively shorter belt ply-formingstrips of predetermined lengths, each starting strip being cut from itsmiddle toward its opposite edges. The apparatus includes two coaxial,rotatable, cylindrical drum-like anvils for the starting strips, and twopairs of normally retracted, non-rotary, heated cutting blades, the twoblades of each pair being mounted for joint reciprocal opposed movementsalong a respective curved path the obliquity of the plane of whichrelative to the mid-circumferential plane of the associated drum can beadjusted, preferably about an axis located in the mid-circumferentialplane of the associated drum and perpendicular to the drum axis, so asto correspond to any desired one of a range of such bias angles. Thecurvature of each path is such that in the mean adjusted positionthereof it is disposed at a substantially constant spacing from theassociated drum surface. The cutting blades of each pair are arranged toabut against each other at the mid-point of their respective path ofmovement, with the parting line of their cutting edge tip region in linewith the associated pivot axis, so that any underlying strip ispenetrated in the middle thereof when the blades are protracted againstthe associated drum surface. Suitable means are also provided foryieldingly urging the blades continuously into contact with theassociated drum surfaces during the separating movements of the bladeswhile performing the cutting operation so as to compensate forvariations in the spacing between their paths of movement and the drumsurfaces engendered by angular adjustments of the paths to other thanthe mean adjusted positions thereof.

15 Claims, 12 Drawing Figures AIENTED 1 5 m5 3 7 32 767 sum 2 OF 6 i NVEN TOR.

WILL/QM C- Ham? PMENTEU Mr 1 arm SHEET Q OF 6 CUT-TO-LENGTH APPARATUSFOR BIAS-CUT TIRE BELT PLY MATERIAL This invention relates to adjustableapparatus for bias-cutting elongated strips of tire belt or breaker plymaterial at any desired one of a range of bias angles so as to formshorter strips suited for use in the building of bias beltsfor beltedpneumatic tires.

in the production of bias-belted tires, the belt structures thereof arebuilt up of strips by belt ply material of predetermined lengths cutfrom relatively longer starting strips having plural reinforcingelements, generally in the form of cords or cables of metallic ornonmetallic filamentary materials, e.g. steel wire, rayon, glass fiber,etc., disposed parallel to one another in each strip and oriented at arelatively low angle to the longitudinal dimension of that strip. In acutting operation of this type, it is preferred to make each cut througha strip at an angle equal to the bias angle of the reinforcing elementsincorporated therein and along the space between two adjacent ones ofsuch elements, both because this makes it easier to cut the strip andbecause it avoids cutting through any of the reinforcing elements eachof which, for maximum belt strength, should extend across the entirewidth of its strip. This principle of cutting has heretofore beenapplied to the bias-cutting of tire carcass ply strips havingreinforcing elements therein oriented at relatively high angles to thelongitudinal strip dimension, for example by means of apparatuses suchas those disclosed in U.S. Pat. Nos.

1,938,787 (Abbott, .lr.), 2,665,757 (Stevens et al.), and 3,429,490(Cantarutti).

Furthermore, to minimize the size of the apparatus and to enhance itsadaptability to the direct transfer of the cut belt ply strips to thebuilding drum associated therewith, it is further preferred to performthe cutting operation on the peripheral surface of a cylindrical drum orlike anvil structure. Such a system for carcass ply material isdisclosed in the aforesaid Abbott patent, and one for belt ply materialis disclosed in U.S. Pat. No. 3,547,732 (Leblond). Both in the lattersystem, however, which utilizes a rotary cutter traversable from oneedge of the ply strip to the other, as well as in the Abbott system, thecutting path is fixed relative to the mid-circumferential plane of thedrum, and the apparatus thus is adapted for cutting at only one givenbias angle. Should a cut at a different angle become necessary,

a different drum and cutter combination must be used. In the Stevens andCantarutti systems, means are provided for effecting angular adjustmentsof the cutting paths, but in each case only relative to a flat or planarstrip-supporting surface.

It is the principal object of the present invention, therefore, toprovide an improved and greatly simplified cut-to-length apparatus forbias-cutting to shorter lengths elongated strips of low angle bias beltply material, while the same are supported on a curved surface, and inparticular to provide adjustable means in such an apparatus to enablethe desired cuts to be made at any one of a range of angles oforientation of the cutting path corresponding to a range of possiblebelt cord bias angles.

Generally speaking, in accordance with the preferred aspects of thepresent invention the objectives thereof are attained by means of anapparatus equipped, in juxtaposition to a stationarily mounted rotatablecylindrical drum or like anvil structure, with a cutter assemblyincluding an elongated arm structure and a cutter sys tem carriedthereby, the latter providing for a cutting action directed obliquely tothe mid-circumferential plane of the drum, and the cutter assembly beingconstructed and arranged so as topermit an adjustment of the obliquityof the cutting direction over a desired angular range.

More particularly, the cutter system includes an arcuate track or guiderail extending lengthwise of the arm structure and obliquely to themid-circumferential plane of the drum, the rail having a curvature whichis such that the spacing between the rail and the peripheral drumsurface radially of the latter remains constant over the entire lengthof the rail in the mean adjusted I position of the cutter assembly. Thearm structure is pivoted intermediate its ends to a rigid stationaryframework, the pivot axis being located in the mid-circumferential planeof the drum and in perpendicular intersecting relation to the axis ofrotation of the drum. Means are also provided for selectively lockingthe arm structure to the framework in any of the available adjustedpositions, so as to fix the obliquity of the rail orientationaccordingly.

Mounted on the rail are two carriages which are interconnected by acrossover cable and pulley system for joint movements in oppositedirections between the middle region 'of the rail and its opposite endregions, such movements of the carriages being effected by means of adouble-acting pneumatic piston and cylinder combination articulated atone end to the arm structure and at the other end to one of thecarriages. Respective heated, non-rotary cutting blades are supported bythe carriages in cooperative relation with the drum surface for movementlengthwise of the carriage path, the plane of movement of the bladesbeing disposed to include the pivot axis of the cutter assembly.Thecutting blades are constructed and arranged to abut against eachother when the carriages are located in the middle region of the railand to define, when in such abutting relation, a composite cutting edgetip region the parting line of which is in line with the pivot axis andthus with the longitudinal centerline of the starting strip then locatedon the drum. Also mounted on the carriages are respective double-actingpneumaparatory to a separating or cutting stroke movement of the blades,for yieldingly urging the blades into continuous contact with the drumsurface during such separating movement, i.e. during the entire cuttingstroke, so as to compensate for any variations in the spacing of thecarriage path from the drum surface along the length of the path such aswill be encountered at any adjusted position of the path other thanone'corresponding to the mean cutting angle, and for retracting theblades from the drum surface and toward the carriages preparatory to andduring the return or approaching movement thereof.

In a particularly advantageous refinement of the apparatus according tothe present invention, a dual cutting arrangement including two suchdrums or anvils and associated angularly adjustable cutter assemblies isprovided, both of the latter being essentially identical in constructionbut arranged in mirror image relation to each other at opposedobliquities relative to the mid-circumferential planes of theirrespective drums. Such an arrangement enables two elongated strips ofbelt ply material, in each of which the reinforcing elements areoriented at a bias angle falling within the contemplated range of suchangles but opposed to the bias angle of the reinforcing elements in theother strip, to be cut contemporaneously on the two drums.

The foregoing and other objects, characteristics and advantages of thepresent invention will be more clearly understood from the followingdetailed description of a preferred embodiment thereof when read inconjunction with the accompanying drawings, in which:

FIG. 1 is a fragmentary plan view of a dual cut-tolength apparatusaccording to the present invention;

FIGS. 1a and lb are fragmentary plan views of two strips of belt plymaterial having mutually oppositely angled reinforcing elementsincorporated therein and intended to be cut to length by the apparatusshown in FIG. 1;

FIG. 2 is a fragmentary elevational view, partly in section, of theright-hand portion of the apparatus shown in FIG. 1, the viewbeing-taken generally in the direction of the arrow A and showing thecutter system from the front and in its inactive state;

FIG. 3 is a view similar to FIG. 2 but showing the cutter systemactivated and in the process of a cutting stroke;

FIG. 4 is another fragmentary elevational view, partly in section, ofthe right-hand portion of the apparatus shown in FIG. 1, this view,however, being taken in the direction of the arrow B and showing thecutter system from the back and in its inactive state;

FIG. 5 is a view similar to FIG. 4 but showing the cutter systemactivated and in the process of a cutting stroke;

' FIG. 6 is a fragmentary top plan view, on an enlarged scale, of thecutter assembly structure per se shown in FIG. 2;

FIG. 7 is an enlarged plan view of a portion of the structure shown inFIG. 6, some parts being broken away to show interior details;

FIG. 8 is a fragmentary front elevational view, on an enlarged scale, ofa portion of the structure shown in FIG. 7, some parts being omitted forclarity;

FIG. 9 is a sectional view taken along the line 9- of FIG. 8; and

FIG. 10 is a sectional view taken along the line l0l0 in FIG. 8, withthe view being drawn rotated through an angle of 90.

Referring now to the drawings in greater detail, the apparatus (FIG. 1)according to the preferred aspects of the present invention comprises apair of coaxial, substantially cylindrical drums or like structures 21and 22 adapted to be codirectionally rotated, preferably in analternating sequence, by means of suitable drive means (not shown). Thedrums constitute a pair of anvils for temporarily supporting respectiveportions of a pair of elongated strips 23 and 24 of oppositely bias-cutrubber and cord belt ply material to be cut into shorter strips ofpredetermined lengths for use in the building of bias belt structuresfor pneumatic tires. The drums are preferably made of steel or otherhard and rigid material and may, for example, be in the form of flangedwheels the outer peripheral surfaces of which are sufficiently wide tosupport the entire widths of the belt ply strips. The means forretaining the strips on the drums may be in the form of well-knownmechanical fasteners or suction devices. Alternatively, in the casewhere the reinforcing elements are in the form of steel wires or cables,the strip-retaining means may be in the form of magnetic means, e.g.masses of magnetic rubber suitably arranged over the peripheral drumsurfaces, as disclosed in the aforesaid Leblond patent, and wheredesired also other types of magnetic elements. For the sake ofsimplicity, and also in view of the fact that such retaining meansconstitute no part of the present invention, they have not beenexplicitly illustrated in the drawings and will not be further describedherein.

The apparatus 20 further comprises a framework 25 located adjacent thedrums 21 and 22 and bridging a portion of the periphery of each of them,and a pair of elongated cutter assemblies 26 and 27 angularly adjustablysupported, in a manner to be more fully explained presently, by theframework 25 in operative juxtaposition to the peripheralstrip-supporting surfaces of the drums 21 .and 22, respectively. Thecutter assemblies are oriented generally obliquely to themid-circumferential planes of their associated drums and thereby providefor correspondingly angled cutting actions, but the respectiveorientations are opposed to each other so as to accommodate the belt plystrips 23 and 24 in the former of'which the reinforcing elements 23a(FIG. 1a) are disposed at a bias angle a relative to the longitudinalstrip dimension opposed to the bias angle B of the reinforcing elements24a (FIG. 1b) in the strip 24. Normally, of course, for tires intendedto have symmetrical and balanced belt structures, these angles will beequal as well.

The framework 25 includes parallel longitudinal frame members 28 and 29rigidly secured at their oppo site ends to parallel cross frame members30 and 31. The framework further includes a transverse rail or crossframe member 32 which is adjustable to a limited degree longitudinallyof the members 28 and 29. For this purpose, the rail 32 is welded at itsopposite ends to a pair of upstanding rigid plates 33 and 34 secured inturn, by welding and with the aid of triangular stiffening braces 35 and36, to respective base plates 37 and 38. The latter are provided withelongated slots and are seated on the frame members 28 and 29,respectively, being releasably secured thereto by means of bolts 39 and40 the shanks of which extend through the slots. All of the variousframe members are preferably made of square cross-section tubular steel.

The cutter assemblies 26 and 27 are of identical construction and areidentically mounted on the framework 25 except, as clearly shown in FIG.1, for being arranged in mirror image relation to each other. A detaileddescription of the cutter assembly 26 will thus suffice for both.Wherever it is deemed advisable, however, parts of the assembly 27 willbe designated by primed duplicates of the reference numerals used todesignate the corresponding parts of the assembly 26.

The cutter assembly 26 comprises an elongated beam-like arm structure 41supporting the respective cutter system 42 (FIGS. 2 to 5) in overlyingrelation to the drums 21. The arm structure 41 is provided with a weldedon, frontwardly directed bracket 43 (see also FIG. 9) to which isrigidly secured an upstanding pivot pin or bolt 44. The latter extendsthrough a flanged bearing 45 (not shown in FIGS. 6, 7 and 9). Thebearing 45 is in turn received in the corresponding bore of a pivotbracket 46 which is welded to a mounting plate 47 bolted to the rail orcross frame member 32. The

axis of the pivot bracket bore and thus the pivot axis for the cutterassembly 26 is located in the mid-circumferential plane of the drum 21and in perpendicular intersecting relation to the axis of rotation ofthe drum (fine adjustment into this position being facilitated by thepresence of the slotted plates 37-38 and the associated locking bolts39-40). A nut 48 (FIG. 1) screwed, above a suitable washer, onto thethreaded extension 44a of the pivot pin 44 projecting beyond the top ofthe bracket 46 serves to secure the arm structure 41 loosely to the rail32.

At its opposite ends, the arm structure 41 is rigidly secured torespective extension plates 49 and 50. In the illustrated arrangement,the plate 49 is provided with an arcuate slot 51 the center of curvatureof which coincides with the said pivot axis, the slot freely receivingtherein the shank of areleasable locking bolt 52 secured at one end toan anchor bracket 53 clamped to the cross member of the framework 25.Correspondingly, the plate carries a locking bolt 54 and a guide pin 55,the locking bolt extending through an arcuate slot 56, and the guide pinthrough an arcuate slot 57, both provided in a guide plate 58 mounted onan anchor bracket 59 clamped to the cross member 31 ofthe framework 25.The slots 46 and 57 have a common center of curvature coinciding withthe pivot axis of the cutter assembly 26, and the paired locking bolt 54and guide pin received in those slots are shown as being disposed in asingle straight line with the said pivot axis.

It will be understood, therefore, that the cutter assemblies 26 and 27can be angularly adjusted about their respective pivot axes, to theextent permitted by the sets of slots 51/56/57 and 51'/56'/57 (FIG. 1),so as to vary the obliquity of their orientations relative to themid-circumferential planes of the drums 21 and 22, and that the cutterassemblies can be locked in any of their adjusted positions by means ofthe sets of'bolts 52/54 and 52'l54' (FIG. 1). The available range ofangular adjustment will, of course, be chosen to accommodate at leastthe range of bias angles (a typical range might be about l824) at whichthe reinforcing elements 23a and 24a may be oriented in the belt plystrips 23 and 24 to be serviced on the apparatus 20.

The cutter system 42 comprises a pair of carriages 60 and 61 (FIGS. 2 to5, 7 and 8) mounted to ride reciprocally by means of respective sets ofwheels 62 and 63 on a curved track or guide rail 64 (see also FIG. 9).The rail 64 extends generally lengthwise of the arm structure 41 andoblique to the mid-circumferential plane of the drum 21, and isconnected at its opposite ends to a pair of brackets 65 and 66 securedto the underside of the arm structure. The curvature of the guide rail64 follows and approximates that of the drum 21, the arrangementpreferably being such that in the mean adjusted position (not shown)'ofthe cutter assembly 26, the spacing between the guide rail and the drumradially of the latter remains constant over the entire length of theguide rail. In the illustrated adjusted position of the cutter assembly26, therefore, the spacing of the guide rail from the drum will beslightly greater in the regions of the two ends of the rail than in themiddle region thereof, while the converse (not shown) would be true withthe cutter assembly shifted to the other side of the mean adjustedposition thereof.

The carriages 60 and 61 are provided with frontwardly directed guidebrackets 67 and 68 through which slidably extend respective sets of tierods 69 and 70 secured at their lowermost ends to respective bladeholders 71 and 72 advantageously constructed in the form of housingscarrying a pair of preferably electrical heating elements (not shown).Two mated cutting blades 73 and 74 with respective active or cuttingedges facing generally in opposite directions away from each other, areremovably secured to the frontwardly facing sides of the housings 71 and72, for example by means of retainer plates 71a-72a and screws 71b-72b,and are in heat exchange relation to the heating elements therein. Attheir upper ends, the tie rods 69 and 70 are rigidly secured torespective cross-heads 75 and 76 which are connected to the respectivefree ends of a pair of piston rods 77 and 78 projecting from a pair ofdouble-acting pneumatic cylinders 79 and 80. The latter are rigidlymounted on the carriages 60 and 61 by means of brackets 81 and 82 (FIGS.8 and 9). The arrangement is such that with the piston rods 77 and 78drawn in, the cutting blades 73 and 74 are retracted toward thecarriages and into their solid-line positions shown in FIG. 8 (see alsoFIG. 2), while upon activation of the cylinders 79 and in the oppositesense the blades are protracted from the carriages and into theirbroken-line positions shown in FIG. 8, i.e. against the surface of thedrum 21 (see also FIGS. 3 and 5) so as to penetrate through the rubberof the belt ply strip 23. For reasons which will become clear as thedescription proceeds, the cutting blades are constructed to define, whenin abutting relation with each other (corresponding to the carriages 60and 61 being in their closed or abutting positions in the middle regionof the guide rail 64), a merged cutting edge tip region the parting lineof which is in line with the pivot axis of the cutter assembly 26 seeFIGS. 7 and 9).

The cylinders 79 and 80 are, as will be more fully explained presently,under the control of a limit switch 83 mounted atop the carriage 61. Theswitch 83 has an operating rod or like member 83a adapted, upon thecarriages reaching their closed positions, to come into contact with andbe displaced out of its normal or rest state by a lug or abutment member84 rigidly mounted atop the carriage 60. For the sake of clarity, theswitch 83/83a and member 84 are not shown in FIGS. 2 and 3. A guide'ordowel pin 85, carried by and projecting from the housing 71 on the sidethereof facing the housing 72, cooperates with a correspondinglydimensioned opening 86 in the housing 72 to ensure proper alignment ofthe cutting blades 73 and 74 in the closed positions of the carriages.

For the purpose of effecting the desired separating and approachingmovements of the carriages and the cutting blades supported thereby, thecarriage 61 is provided with an upstanding rigid bracket or lug 87 towhich one end of a piston rod 88 projecting from a double-actingpneumatic cylinder 89 is articulated at 88a. The other end of thecylinder 89 is articulated at 89a to a cross bracket or strut 90 rigidlysecured to the arm structure 41. concomitantly, to constrain thecarriages to joint movements in opposite directions, the carriages areinterconnected with each other by a crossover cable system. One half ofthe system includes a cable 91 having one end thereof fixedly anchoredto the carriage 60 at 91a, its medial region trained about a pair ofpulleys 92 mounted on the bracket 65, and its other end yieldinglyanchored to a bolt 93 extending slidably through a bracket 94 fixed tothe carriage 61, the bolt 93 having a compression spring 95 coaxiallyinterposed between the bracket 94 and a flange or shoulderstructure 93aprovided on the bolt. Similarly, the other half of the system includes asecond cable 96 having one end thereof fixedly anchored to the carriage61 at 96a, its medial region trained about a pair of pulleys 97 securedto the bracket 66, and its other end yieldingly anchored to a bolt 98extending slidably through a bracket 99 fixed to the carriage 60, thebolt 98 having a compression spring 100 coaxially interposed between thebracket 99 and a shoulder or flange structure 98a provided on the bolt.

As will be clear, therefore, when the piston rod 88 is protracted fromthe position shown in FIGS. 2 and 4 to the position shown in FIGS. 3 and5, the carriage 61 is pushed along the rail 64 from the middle region ofthe latter toward the bracket 66, and simultaneously the carriage 60 ispulled in the opposite direction through the intermediary of the cable91. Upon reverse actuation of the piston rod 88 thereafter, the carriage61 will be pulled away from the bracket 66 and toward the middle regionof the rail 64, and simultaneously the carriage 60 will be pulled towardthe middle region of the rail 64 and thus toward the carriage 61 throughthe intermediary of the cable 96.

The apparatus 20 also includes means for controlling the activation ofthe cylinders 79, 80 and 89 in one sense or the other at differentstages of each operating cycle. Included in the control means is thealready mentioned limit switch 83 the operating member 83a of which isadapted to be engaged and pushed in upon the carriages 60 and 61 beingin their closed positions, which are their starting positions for eachcycle. In addition, a limit switch 101 is mounted on the bracket 66, theswitch 101. being provided with an operating arm or member 102 (FIGS. 4and 5) adapted to be contacted and displaced by an adjunct (not shown)of the carriage 61 when the latter reaches a predetermined point of itsoutward travel. Two additional limit switches 103 and 104 are mounted onthe carriages 60 and 61, respectively, e.g. by means of suitablebrackets 105 and 106 (FIG. these switches having operating arms ormembers 107 and 108 adapted to be contacted and displaced, uponcompletion of the protraction of the cutting blades 73 and 74, bycorresponding cam members or like adjuncts 109 and 1 10 (FIGS. 2, 3 and8) secured to the cross-heads 75 and 76.

The various switches are connected into the control circuitry (notshown) of the apparatus, suitable junction boxes 111 and 112 on the armstructure 41 and junction boxes 1 13 and 114 on the carriages 60 and 61being provided for the respective electrical cables (not shown). Theswitches serve to operate the control valves (not shown) through whichfluid pressure can be admitted to one end or the other of each of thecylinders 79, 80 and 89. The arrangement is such that when the cuttingblades are retracted, the carriages must be in their closed positions,i.e. the switch 83 must be activated and the switch 101 deactivated, topermit admission of fluid pressure into the blind ends of the cylinders79 and 80 and the consequent protraction of the cutting blades 73 and 74to take place; the blades must be protracted or down in the closedposition of the carriages, i.e. the switches 83, 103 and'l04 must beactivated, to permit admission of fluid pressure into the blind end ofthe cylinder 89 and the consequent outward travel of the carriages forthe cutting stroke to take place; when the cutting blades areprotracted, the carriages must be in the opened positions, i.e. theswitch 101 must be activated, to permit admission of fluid pressure intothe piston rod ends of the cylinders 79 and 80 and the consequentretraction of the blades from the drum to take place; and the bladesmust be retracted or up in the opened positions of the carriages, i.e.the switches 103 and 104 must be deactivated and the switch 101activated, to permit admission of fluid pressure into the piston rod endof the cylinder 89 and the consequent return movements of the carriagesinto their closed and starting positions to take place. The controlcircuitry (which normally will also include means for starting andstopping the operation of the apparatus, means for selectively settingthe same for automatic or manual operation, malfunction-responsivesafety control means, and other components conventionally used in suchcircuits) has not been explicitly illustrated in the drawings, however,since the arrangement and interconnections of the various switches andof the associated solenoids, relays and other related operatinginstrumentalities required to enable the apparatus to function asdescribed, will be within the ken of those skilled in the art.

The operation of the apparatus according to the present invention forcutting the two starting elongated belt ply strips 23 and 24 intorespective shorter strips (not shown) of lengths dictated by theintended belt circumferences of the tires then being built, is asfollows:

It is assumed that a bias-cutting operation, performed on startingstrips 23 and 24 initially fed in properly centered relation into therespective drums 21 and 22 in any suitable manner has been completed.The two cutter assemblies 26 and 27 are in their respective adjustedpositions required to orient the directions of movement of the two pairsof carriages and the associated cutting blades at respective obliqueangles to the mid-circumferential planes of the drums, i.e. to the stripfeed directions, corresponding to the bias angles of the reinforcingelements 23a and 24a in the strips. On both drums, the now leading edgeregions 23b and 24b of the respective'strips are retained in place bysuction, mechanical fasteners or magnetic means, as hereinbeforedescribed. In the illustrated state, the drum 21 is being rotated toadvance the required length of the strip 23 past the associated cuttersystem 42, the latter during this time being in the stage thereof shownin FIGS. 2, 4 and 8, with the carriages in their closed positions andthe cutting blades up, i.e. retracted. At the same time, the drum 22is'halted with the leading edge 24b of the strip 24 just in front of thepivot axis of the cutter assembly 27 while the cutting blades thereofare retracted and being returned to their starting positions.

Referring now exclusively to the drum 21 and cutter assembly 26, whenthe drum again stops rotating, the cutting blades 73 and 74 areprotracted toward the drum and are forced through the rubber of thestrip 23 against the surface of the drum. Thereupon, as soon as theblades are fully down, the activation of the switches 103 and 104enables fluid pressure to be admitted into the blind end of the cylinder89 to start the outward or separating travel of the carriages 60 and 61and thereby the performance of the cutting operation.

It will be understood that by virtue of the alignment of the partingline of the cutting edge tip region of the blades 73 and 74, when thesame are in abutting relation with each other, with the pivot axis ofthe cutter assembly 26, as previously described, the initial penetrationof the strip 23 by the cutting blades occurs precisely on thelongitudinal centerline of the strip. The latter thus is cut from itsmiddle toward its opposite edges, and with the blades being non-rotary,flat and thin, as shown, and moving in a plane the obliquity of whichcorresponds to the bias angle a of the reinforcing elements 23a in thestrip, the blades cut the strip entirely lengthwise of and between twoadjacent ones of the said reinforcing elements. The pressure in each ofthe cylinders 79 and 80 is, moreover, maintained in any suitable mannerat a level sufficient not only to effect the initial penetration butalso to enable the cylinders to compensate for the slight increase inthe spacing of the guide rail or track 64 from the drum surface, in thedirection going from the middle of the rail toward the ends thereof, bycontinuously urging the individual blades to remain in contact with thedrum surface throughout the cutting stroke. (In adjusted positions ofthe cutter assembly on the other side of the mean adjusted position, ofcourse, the cylinders compensate for the slight decrease in the drum torail spacing lengthwise of the latter by providing a yielding back-upforce on the cutting blades so as to permit the same'to follow the drumsurface contours without risk of damage). Distortion of the strip aswell as the possibility of the blades either jumping across or cuttingthrough any of the reinforcing elements are thereby effectivelyeliminated, which leads to a substantial reduction in scrap losses andalso lessens the likelihood of misalignment of the plies duringformation of the ultimate belt on the building drum. Both the initialpenetration and the subsequent cutting are, in addition, greatlyfacilitated by the heating of the blades, and the attachment of thelatter to the heater housings 71 and 72 in the manner shown enablesblades to be easily removed for sharpening and/or replacement.

Reverting now to the operation of the apparatus, when the cutting strokeof the blades 73 and 74 is finished, the switch 101 is activated inresponse to the carriage 60 reaching the end of its travel path andeffects the retraction of the blades. The consequent deactivation of theswitches 103 and 104 then enables fluid pressure to be admitted into thepiston rod end of the cylinder '89 to return the carriages 60 and 61 totheir starting positions. This action can thus take place without anyrisk of the blades either damaging the strip material on the drum orbeing damaged themselves. At the same time, the drum 21 is again rotatedto advance the leading edge region 23b of the'now severed strip to atransfer device (not shown) juxtaposed to and cooperating with the drumto enable the strip to be removed from the drum and transferred to thebelt building location. As soon as the carriages again reach theirstarting positions, the switch 83 is reactivated and the control circuitis conditioned to start the next cycle in response to the drum 21 comingto a halt with a sufficient new length of the starting strip material 23having passed the cutting line.

Concurrently with the foregoing, the operation of the drum 22 and cutterassembly 27 proceeds in a manner identical, except for the orientationof the cutting line relative to the strip feed path, to the operation ofthe drum 21 and cutter assembly 26 as so far described. Repetition ofthat description will thus not be necessary herein. It should merely benoted that the two halves of the apparatus can be operated jointly or intandem,

with the latter approach being preferred for a fullfledged manufacturingrun since it enables the transfer device to take the severed strips oneat a time from each of the drums in a continuous alternating sequence,so that the strips can be combined directly, without inversion of eitherone, into mutually superposed relation placing the reinforcing elementsin each ply of the so-formed belt structure in crossing relation tothose of the other ply.

It will be understood, of course, that in addition to the transfermechanism there will be various other pieces of equipment normallyassociated with the apparatus 20, i.e. the means for feeding the strips23 and 24 to and centering them on the drums, the tire buildingmachinery per se, etc. These do not, however, constitute parts of thepresent invention, and thus they have been neither illustrated nordescribed in detail herein.

It will be further understood that the foregoing description of apreferred embodiment of the present invention is for purposes ofillustration only, and that the various structural and operationalfeatures herein disclosed are susceptible to a number of modificationsand changes none of which entails any departure from the spirit andscope of the present invention as defined in the hereto appended claims.Merely by way-of example, the available range of angular adjustments ofthe cutter assemblies may be larger than the typical 6 range alluded toand may, in fact, be larger than the possible range of bias angles to beencountered in strips being cut to length. Since space is normally at apremium in any tire plant, however, it will be found most advantageousto provide an adjustability range no larger than the bias angle range tobe dealt with, which will enable any given apparatus 20 to occupy theminimum possible amount of space. Again, the starting strip need not beapplied to the drum in precisely centered relation thereto. in such acase, the strip will be pierced off the centerline. This, however, willhave no adverse effect even though one blade will finish its cut beforethe other, since the retaining means will hold the strip in place on thedrum until the second blade finishes its cut.

Having thus described the invention, what is claimed and sought to beprotected by Letters Patent is:

1. In an apparatus for bias-cutting an elongated starting strip ofrubberized tire belt ply material, which has a multiplicity of parallelcord-like reinforcing elements therein obliquely oriented at a givenbias angle to the longitudinal strip dimension, into at least onerelatively shorter belt ply-forming strip, with the cutting of startingstrip being initiated at an interior'region thereof and proceedingtherefrom toward its opposite edges in a line parallel to saidreinforcing elements, which apparatus includes a. a rotatable drumhaving a hard peripheral surface constituting an anvil for supportingthe full width of a predetermined length portion of said starting stripduring a cutting operation,

b. a pair of non-rotary cutting blades, and

c. carriage means supporting said cutting blades and mounted forreciprocal separating and approaching movements along an arcuate pathspaced radially from said drum surface and included in a plane normal tosaid drum surface and oriented obliquely to the mid-circumferentialplane of said drum at an angle corresponding to the bias angle of saidreinforcing elements in said starting strip,

d. each of said carriage means being arranged to move between anintermediate region of said path, in which region said cutting bladesabut against each other, and a respective one of the end regions of saidpath, and

, e. said cutting blades when in abutting relation presenting a cuttingedge tip configuration the parting line of which overlies said interiorregion of said starting strip;

the improvement comprising:

A. means for angularly adjusting the obliquity of said path relative tosaid mid-circumferential plane of said drum over a range of angles oforientation corresponding at least to a possible range of different biasangles at which said reinforcing elements may be oriented in differentstarting strips to be cut;

B. said path having a curvature such that the spacing between said pathand said drum surface normally of the latter 1. is constant lengthwiseof said path in one adjusted position thereof corresponding to aselected one of said different possible bias angles, and

2. varies lengthwise of said path in all other adjusted positionsthereof;

. C. means operatively connected with said carriage means for jointlymoving the same and thus said cutting blades to effect saidseparatingand approaching movements thereof; and

D. means operatively connected with said cutting blades 7 l. forprotracting said cutting blades from said carriage means and againstsaid drum surface, and thus through said starting strip when the same islocated on said drum surface, preparatory to a separating movement ofsaid cutting blades,

2. for yieldingly urging said cutting blades, upon protraction thereof,into continuous contact with said drum surface during a separatingmovement of said cutting blades and the performance of a cuttingoperation, thereby to compensate for any variation in said spacing ofsaid path from said drum surface lengthwise of said path which resultswhen the latter is in any other than said one adjusted position thereof,and

3. for retracting said cutting blades from said drum surface and towardsaid carriage means preparatory to and during an approaching movement ofsaid cutting blades subsequent to completion of the cutting operation. If I 2. An apparatus as claimed in claim 1 which also includes anadditional section comprising duplicates of said rotatable drum, of saidpaired non-rotary cutting blades, and of said named means associatedtherewith, all substantially identical in construction and arrangementwith the corresponding elements of the firstrecited apparatus sectionexcept for the fact that the duplicate carriage means are mounted formovement along an arcuate path included in a plane the obliquityoriented at a bias angle opposed to that of said reinforcing elements insaid first-named starting strip.

3. An apparatus as claimed in claim 1, wherein said curvature of saidpath is such as to provide said constant spacing between said drumsurface and said path in the mean adjusted position of the latter.

4. An apparatus as claimed in claim 1, wherein said means for adjustingthe obliquity of said path relative to said mid-circumferential plane ofsaid drum is constructed and arranged for angular movement about a pivotaxis located in perpendicular intersecting relation to the axis ofrotation of said drum and included in theplane of movement of saidcutting blades.

5. An apparatus as claimed in claim 4, wherein said pivot axis isincluded in said mid-circumferential plane of said drum, said cuttingblades being constructed and arranged so as to have said parting line ofsaid cutting edge tip configuration thereof located in line with saidpivot axis and the longitudinal centerline of said starting strip whensaid cutting blades are in said abutting relation thereof.

6. An apparatus as claimed in claim 5, wherein said curvature of saidpath is such as to provide said constant spacing between said drumsurface and said path in the mean adjusted position of the latter.

7. An apparatus as claimed in claim 1, further comprising an armstructure supporting said carriage means defining said path of movementthereof, and said adjusting means comprising means mounting said armstructure for displacement into a number of different positions eachproviding a different obliquity of said path within said range of anglesof orientation, and means for selectively locking said arm structure ineach of said different positions thereof.

8. An apparatus as claimed in claim 7, said mounting means comprisingfixed frame means juxtaposed to said drum, and a pivot boltinterconnecting said frame means and said arm structure intermediate theends of the latter, said locking means comprising a pair of cooperatingcurved slot and locking bolt combinations interconnecting said framemeans and said arm structure at said opposite ends of the latter,respectively, each of said slots having its center of curvaturecoinciding with the axis of said pivot bolt and subtending an angle atleast equal to said range of angles of orientation.

9. An apparatus as claimed in claim 8, said cutting blades beingconstructed and arranged so as to have said parting line of said cuttingedge tip configuration thereof located in line with said axis of saidpivot bolt when said cutting blades are in said abutting relationthereof. v

10. An apparatus as claimed in claim 8, said pivot bolt being arrangedto have said axis thereof located in said mid-circumferential plane ofsaid drum and in perpendicular intersecting relation to the axis ofrotation of said drum, and said cutting blades being constructed andarranged so as to have said parting line of said cutting edge tipconfiguration thereof located in line with said axis of said pivot boltwhen said cutting blades are fining said path of movement thereof, and apair of blade holder means supported by said carriage means,respectively, for movement therewith, each of said cutting blades beingremovably connected to a respective one of said blade holder means, saidprotracting/urging/retracting means being connected with said bladeholder means, and said guide rail being of arcuate configuration andimparting said curvature to said path.

12. An apparatus as claimed in claim 11, further comprising respectiveheater means carried by said blade holder means in heat exchangerelation to said cutting blades for heating the latter to facilitate thecutting operations thereof.

13. An apparatus as claimed in claim 11, said guide rail being locatedlaterally of said axis of said pivot bolt, and said blade holder meanssupporting said cutting blades laterally of said guide rail and incoplanar relation with both each other and said axis of said pivot bolt.

14. An apparatus as claimed in claim 13, said means for moving saidcutting blades comprising a doubleacting fluid pressure piston andcylinder combination articulated at one end to said arm structure and atthe other end to one of said carriage means, and a crossover cablesystem interconnecting said carriage means with one another to constrainthe same to either said separating or said approaching movements uponappropriate activation of said piston and cylinder combination in onesense or the other.

15. An apparatus as claimed in claim 13, saidprotracting/urging/retracting means comprising a pair of double-actingfluid pressure piston and cylinder combinations mounted on said carriagemeans, each of said piston and cylinder combinations having one memberthereof fixedly secured to its respective carriage means and having theother member thereof movable relative to said one member and secured tothe associated one of said blade holder means.

1. In an apparatus for bias-cutting an elongated starting strip ofrubberized tire belt ply material, which has a multiplicity of parallelcord-like reinforcing elements therein obliquely oriented at a givenbias angle to the longitudinal strip dimension, into at least onerelatively shorter belt ply-forming strip, with the cutting of startingstrip being initiated at an interior region thereof and proceedingtherefrom toward its opposite edges in a line parallel to saidreinforcing elements, which apparatus includes a. a rotatable drumhaving a hard peripheral surface constituting an anvil for supportingthe full width of a predetermined length portion of said starting stripduring a cutting operation, b. a pair of non-rotary cutting blades, andc. carriage means supporting said cutting blades and mounted forreciprocal separating and approaching movements along an arcuate pathspaced radially from said drum surface and included in a plane normal tosaid drum surface and oriented obliquely to the mid-circumferentialplane of said drum at an angle corresponding to the bias angle of saidreinforcing elements in said starting strip, d. each of said carriagemeans being arranged to move between an intermediate region of saidpath, in which region said cutting blades abut against each other, and arespective one of the end regions of said path, and e. said cuttingblades when in abutting relation presenting a cutting edge tipconfiguration the parting line of which overlies said interior region ofsaid starting strip; the improvement comprising: A. means for angularlyadjusting the obliquity of said path relative to saidmid-circumferential plane of said drum over a range of angles oforientation corresponding at least to a possible range of different biasangles at which said reinforcing elements may be oriented in differentstarting strips to be cut; B. said path having a curvature such that thespacing between said path and said drum surface normally of thelatter
 1. is constant lengthwise of said path in one adjusted positionthereof corresponding to a selected one of said different possible biasangles, and
 2. varies lengthwise of said path in all other adjustedpositions thereof; C. means operatively connected with said carriagemeans for jointly moving the same and thus said cutting blades to effectsaid separating and approaching movements thereof; and D. meansoperatively connected with said cutting blades
 1. for protracting saidcutting blades from said carriage means and against said drum surface,and thus through said starting strip when the same is located on saiddrum surface, preparatory to a separating movement of said cuttingblades,
 2. for yieldingly urging said cutting blades, upon protractionthereof, into continuous contact with said drum surface during aseparating movement of said cutting blades and the performance of acutting operation, thereby to compensate for any variation in saidspacing of said path from said drum surface lengthwise of said pathwhich results when the latter is in any other than said one adjustedposition thereof, and
 3. for retracting said cutTing blades from saiddrum surface and toward said carriage means preparatory to and during anapproaching movement of said cutting blades subsequent to completion ofthe cutting operation.
 2. varies lengthwise of said path in all otheradjusted positions thereof; C. means operatively connected with saidcarriage means for jointly moving the same and thus said cutting bladesto effect said separating and approaching movements thereof; and D.means operatively connected with said cutting blades
 2. An apparatus asclaimed in claim 1 which also includes an additional section comprisingduplicates of said rotatable drum, of said paired non-rotary cuttingblades, and of said named means associated therewith, all substantiallyidentical in construction and arrangement with the correspondingelements of the first-recited apparatus section except for the fact thatthe duplicate carriage means are mounted for movement along an arcuatepath included in a plane the obliquity of which to themid-circumferential plane of the duplicate drum is opposed to theobliquity of the plane of said path of said first-named carriage meansto said mid-circumferential plane of said first-named drum, thereby toenable the contemporaneous bias-cutting, in said additional apparatussection, of a second starting strip in which the respective reinforcingelements are oriented at a bias angle opposed to that of saidreinforcing elements in said first-named starting strip.
 2. foryieldingly urging said cutting blades, upon protraction thereof, intocontinuous contact with said drum surface during a separating movementof said cutting blades and the performance of a cutting operation,thereby to compensate for any variation in said spacing of said pathfrom said drum surface lengthwise of said path which results when thelatter is in any other than said one adjusted position thereof, and 3.for retracting said cutTing blades from said drum surface and towardsaid carriage means preparatory to and during an approaching movement ofsaid cutting blades subsequent to completion of the cutting operation.3. An apparatus as claimed in claim 1, wherein said curvature of saidpath is such as to provide said constant spacing between said drumsurface and said path in the mean adjusted position of the latter.
 4. Anapparatus as claimed in claim 1, wherein said means for adjusting theobliquity of said path relative to said mid-circumferential plane ofsaid drum is constructed and arranged for angular movement about a pivotaxis located in perpendicular intersecting relation to the axis ofrotation of said drum and included in the plane of movement of saidcutting blades.
 5. An apparatus as claimed in claim 4, wherein saidpivot axis is included in said mid-circumferential plane of said drum,said cutting blades being constructed and arranged so as to have saidparting line of said cutting edge tip configuration thereof located inline with said pivot axis and the longitudinal centerline of saidstarting strip when said cutting blades are in said abutting relationthereof.
 6. An apparatus as claimed in claim 5, wherein said curvatureof said path is such as to provide said constant spacing between saiddrum surface and said path in the mean adjusted position of the latter.7. An apparatus as claimed in claim 1, further comprising an armstructure supporting said carriage means defining said path of movementthereof, and said adjusting means comprising means mounting said armstructure for displacement into a number of different positions eachproviding a different obliquity of said path within said range of anglesof orientation, and means for selectively locking said arm structure ineach of said different positions thereof.
 8. An apparatus as claimed inclaim 7, said mounting means comprising fixed frame means juxtaposed tosaid drum, and a pivot bolt interconnecting said frame means and saidarm structure intermediate the ends of the latter, said locking meanscomprising a pair of cooperating curved slot and locking boltcombinations interconnecting said frame means and said arm structure atsaid opposite ends of the latter, respectively, each of said slotshaving its center of curvature coinciding with the axis of said pivotbolt and subtending an angle at least equal to said range of angles oforientation.
 9. An apparatus as claimed in claim 8, said cutting bladesbeing constructed and arranged so as to have said parting line of saidcutting edge tip configuration thereof located in line with said axis ofsaid pivot bolt when said cutting blades are in said abutting relationthereof.
 10. An apparatus as claimed in claim 8, said pivot bolt beingarranged to have said axis thereof located in said mid-circumferentialplane of said drum and in perpendicular intersecting relation to theaxis of rotation of said drum, and said cutting blades being constructedand arranged so as to have said parting line of said cutting edgE tipconfiguration thereof located in line with said axis of said pivot boltwhen said cutting blades are in said abutting relation thereof.
 11. Anapparatus as claimed in claim 10, further comprising a guide railcarried by said arm structure, said guide rail supporting said carriagemeans and defining said path of movement thereof, and a pair of bladeholder means supported by said carriage means, respectively, formovement therewith, each of said cutting blades being removablyconnected to a respective one of said blade holder means, saidprotracting/urging/retracting means being connected with said bladeholder means, and said guide rail being of arcuate configuration andimparting said curvature to said path.
 12. An apparatus as claimed inclaim 11, further comprising respective heater means carried by saidblade holder means in heat exchange relation to said cutting blades forheating the latter to facilitate the cutting operations thereof.
 13. Anapparatus as claimed in claim 11, said guide rail being locatedlaterally of said axis of said pivot bolt, and said blade holder meanssupporting said cutting blades laterally of said guide rail and incoplanar relation with both each other and said axis of said pivot bolt.14. An apparatus as claimed in claim 13, said means for moving saidcutting blades comprising a double-acting fluid pressure piston andcylinder combination articulated at one end to said arm structure and atthe other end to one of said carriage means, and a crossover cablesystem interconnecting said carriage means with one another to constrainthe same to either said separating or said approaching movements uponappropriate activation of said piston and cylinder combination in onesense or the other.
 15. An apparatus as claimed in claim 13, saidprotracting/urging/retracting means comprising a pair of double-actingfluid pressure piston and cylinder combinations mounted on said carriagemeans, each of said piston and cylinder combinations having one memberthereof fixedly secured to its respective carriage means and having theother member thereof movable relative to said one member and secured tothe associated one of said blade holder means.